Video data processing system, video server, gateway server, and video data management method

ABSTRACT

A system includes a reading unit reading first management information including a first item specifying video data and the video data from a storage medium, a storage unit recording second management information including the first item obtained from the first management information and the video data transferred from the reading unit, a memory storing third management information including the first item and a second item specifying a transfer or no transfer of the video data, and a controller transferring the first management information to the memory from the reading unit, updating the second item of the third management information in response to the transfer of the video data, and controlling the transfer of the video data in the video content which is designated by a read request from one of the reading unit and the storage unit to the outside based on the second item of the third management information.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromprior Japanese Patent Applications No. 2008-236967, filed Sep. 16, 2008;and No. 2009-142119, filed Jun. 15, 2009, the entire contents of both ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for processing video data, avideo server, a gateway server, and a method for managing and processingvideo data.

2. Description of the Related Art

In the conventional video data processing system, a video content ofvideo contents are supplied from a video tape recorder (VTR) on which amoving picture and audio signals output from a video camera are recordedas the video content, are encoded and converted into a video file, andare recorded on a storage medium of a video server. When non-linearediting is carried out, an editing unit accesses the video server of thevideo data processing system, and reads a video file from the storagemedium of the video server. Further, the editing unit carries outnon-linear editing of the read video file. For this reason, in order tocarry out non-linear editing, the imaged image must be encoded, and mustwait until it is recorded on the storage medium of the video server.

Incidentally, in recent years, the storage medium of the video camerahas been switched from a tape to a randomly accessible medium such as ahard disk, a semiconductor memory, and the like. When a semiconductormemory or the like is used as the storage medium of the video camera, itbecomes possible to directly record a video signal from the video cameraon the storage medium as a video file. As a result of this, it becomesunnecessary to subject the video signal from the VTR to encodingprocessing, and hence it becomes possible to shorten the waiting time upto the starting of the non-linear editing. However, the time fortransferring the video file that has been imaged to the storage mediumof the video server, and recording the video file is not resolved yet.

It should be noted that in order to shorten the time for transferringthe video file to the video server, there is proposed, in Jpn. Pat.Appin. KOKAI Publication No. 2005-51491, a technique wherein an imagesignal, i.e., video data with low resolution and a small amount of datais transferred, editing work is then carried out, and then only dataconforming to the editing content is transferred is proposed. However,although the waiting time is shortened by transferring data of lowresolution, the waiting time is not eliminated. Further, using thismethod poses a problem that it is difficult to confirm the video data atthe original image quality at the editing time.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide a system for processingvideo data, a video server, a gateway server, and a method capable ofstarting non-linear editing of an acquired video file without waitingtime.

According to an aspect of the present invention, there is provided asystem for reading a video content from a storage medium, the videocontent being recorded in preset units of video data in the storagemedium, the system comprising: a reading unit which is connected to thestorage medium to generate a setting signal, and reads first managementinformation including a first item specifying the units of video data inresponse to the setting signal and the unit or units of video data inthe video content from the storage medium; a storage unit which recordssecond management information including the first item obtained from thefirst management information and the unit or units of video data in thevideo content transferred from the reading unit; a memory which storesthird management information including the first item and a second itemspecifying a transfer or no transfer of the unit or units of video datafrom the reading unit to the storage unit; and a controller whichtransfers the first management information to the memory from thereading unit in response to the setting signal to update the thirdmanagement information, updates the second item of the third managementinformation in response to the transfer of the unit or units of videodata from the reading unit to the storage unit, and controls thetransfer of the unit or units of video data in the video content whichis designated by a read request from the outside of the system from oneof the reading unit and the storage unit to the outside of the system inaccordance to the second item of the third management information.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a view showing the configuration of a video data processingsystem according to a first embodiment of the present invention.

FIG. 2 is a view showing an example of a file management table stored ina memory shown in FIG. 1.

FIG. 3 is a view showing an example of a block management table storedin a memory shown in FIG. 1.

FIG. 4 is a view showing an example of video data written to a logicalblock in a removable storage medium and a storage unit shown in FIG. 1.

FIG. 5 is a sequence diagram of a case where the video data processingsystem of FIG. 1 prepares to transfer a video file recorded on aremovable storage medium to a storage unit, and prepares to carry outnon-linear editing of the video file by using a non-linear editing unit.

FIG. 6A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 5 is carried out.

FIG. 6B is a view showing the states of the memory in the case where theprocessing of FIG. 5 is carried out.

FIG. 6C is a view showing the states of the storage unit in the casewhere the processing of FIG. 5 is carried out.

FIG. 7 is a sequence diagram of a case where after the processing ofFIG. 5 is completed, a video file is transferred from the removablestorage medium to the storage unit in the background.

FIG. 8A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 7 is carried out.

FIG. 8B is a view showing the states of the memory in the case where theprocessing of FIG. 7 is carried out.

FIG. 8C is a view showing the states of the storage unit in the casewhere the processing of FIG. 7 is carried out.

FIG. 9 is a sequence diagram of a case where after the preparation ofFIG. 5 is completed, a request to read a video file recorded on theremovable storage medium is received from the non-linear editing unit.

FIG. 10A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 9 is carried out.

FIG. 10B is a view showing the states of the memory in the case wherethe processing of FIG. 9 is carried out.

FIG. 10C is a view showing the states of the storage unit in the casewhere the processing of FIG. 9 is carried out.

FIG. 11 is a sequence diagram of a case where after the preparation ofFIG. 5 is completed, a request to write a video file that has alreadybeen edited is received from the non-linear editing unit.

FIG. 12A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 11 is carried out.

FIG. 12B is a view showing the states of the memory in the case wherethe processing of FIG. 11 is carried out.

FIG. 12C is a view showing the states of the storage unit in the casewhere the processing of FIG. 11 is carried out.

FIG. 13 is a sequence diagram of a case where a video file istransferred from the removable storage medium to the storage unit in thebackground in the procedure different from the transfer processing shownin the sequence diagram of FIG. 7.

FIG. 14A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 13 is carried out.

FIG. 14B is a view showing the states of the memory in the case wherethe processing of FIG. 13 is carried out.

FIG. 14C is a view showing the states of the storage unit in the casewhere the processing of FIG. 13 is carried out.

FIG. 15 is a view showing the configuration of a video data processingsystem according to a second embodiment of the present invention.

FIG. 16 is a sequence diagram of a case where the video data processingsystem of FIG. 15 prepares to transfer a video file recorded on aremovable storage medium to a video server, and prepares to carry outnon-linear editing of the video file by using a non-linear editing unit.

FIG. 17A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 16 is carried out.

FIG. 17B is a view showing the states of the gateway server in the casewhere the processing of FIG. 16 is carried out.

FIG. 17C is a view showing the states of the video server in the casewhere the processing of FIG. 16 is carried out.

FIG. 18 is a sequence diagram of a case where after the processing ofFIG. 16 is completed, a video file is transferred from the removablestorage medium to the video server in the background.

FIG. 19A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 18 is carried out.

FIG. 19B is a view showing the states of the gateway server in the casewhere the processing of FIG. 18 is carried out.

FIG. 19C is a view showing the states of the video server in the casewhere the processing of FIG. 18 is carried out.

FIG. 20 is a sequence diagram of a case where after the preparation ofFIG. 16 is completed, a request to read a video file recorded on theremovable storage medium is received from a non-linear editing unit.

FIG. 21A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 20 is carried out.

FIG. 21B is a view showing the states of the gateway server in the casewhere the processing of FIG. 20 is carried out.

FIG. 21C is a view showing the states of the video server in the casewhere the processing of FIG. 20 is carried out.

FIG. 22 is a sequence diagram of a case where after the preparation ofFIG. 16 is completed, a request to write a video file that has alreadybeen edited is received from the non-linear editing unit.

FIG. 23A is a view showing the states of the removable storage medium inthe case where the processing of FIG. 22 is carried out.

FIG. 23B is a view showing the states of the gateway server in the casewhere the processing of FIG. 22 is carried out.

FIG. 23C is a view showing the states of the video server in the casewhere the processing of FIG. 22 is carried out.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention will be described below in detailwhile referring to the accompanying drawings.

First Embodiment

FIG. 1 is a schematic view showing the configuration of a video dataprocessing system 10 according to a first embodiment of the presentinvention. The video data processing system 10 is provided with areading unit 11, and a video server 12. The reading unit 11 has aninsertion opening through which a removable storage medium 20 isinserted into the reading unit 11 and can be randomly accessed to thereading unit 11. A non-linear editing unit 30 is connected to the videoserver 12.

A video image or picture image taken by a camera 40 is converted into avideo file, and is recorded on a removable storage medium 20. On theremovable storage medium 20, a file management table for managing therecorded video file, and block management table for managing therecording state of the storage medium are recorded in advance, and if avideo file is recorded thereon, these tables are updated in accordancewith the recorded video file. It should be noted that the filemanagement table and the block management table stored in the removablestorage medium 20 have same structures as file management tables andblock management tables stored in a storage unit 121 and a memory 122 inthe video server 12. The structures of the file management tables andthe block management tables will be described later in detail.

The removable storage medium 20 is constituted of, for example, asemiconductor storage medium such as a flash memory and the like, or ahard disk or the like, and is set in the reading unit 11 through theinsertion opening. The video file recorded on the removable storagemedium 20 is read by the reading unit 11, and is transferred to thevideo server 12.

The video server 12 is provided with a storage unit 121, a memory 122,and a processing unit 123. The storage unit 121 is a storage mediumconstituted of a semiconductor storage medium such as a flash memory andthe like, or a hard disk or the like. As the memory 122, for example, arandom access memory (RAM) is used. The processing unit 123 is embodiedas a controller for controlling the units in the video server 12, and isconfigured by a microprocessor such as a central processing unit (CPU)or the like.

When the removable storage medium 20 is connected to the reading unit11, the processing unit 123 updates the file management table and theblock management table recorded in advance in each of the storage unit121 and memory 122, prepares to transfer a video file recorded on theremovable storage medium 20 to the storage unit 121, and prepares tocarry out non-linear editing of the video file by using the non-linearediting unit 30.

If the preparation for transfer of the video file recorded on theremovable storage medium 20 is completed, the processing unit 123transfers the video file to the storage unit 121, and updates the filemanagement tables and block management tables of the memory 122 andstorage unit 121.

If the processing unit 123 receives a request to read the video filefrom the non-linear editing unit 30, the unit 123 outputs the requestedvideo file to the non-linear editing unit 30 by referring to the filemanagement tables and block management tables recorded on removablestorage medium 20, memory 122, and storage unit 121.

If the processing unit 123 receives a request to write the video filefrom the non-linear editing unit 30, the unit 123 records the video filein the storage unit 121, and updates the file management tables andblock management tables of the storage unit 121 and memory 122.

The non-linear editing unit 30 is a device for carrying out non-linearediting of the video file. The non-linear editing unit 30 accesses thevideo server 12, and requests the video server 12 to read a video filedesired to be edited. Further, the non-linear editing unit 30 requeststhe video server 12 to write the video file that has already beenedited.

Next, the processing operation of the video data processing system 10configured as described above will be described below in detail.Specific examples of the file management table and the block managementtable in this embodiment are shown in FIGS. 2 and 3, respectively. FIG.2 is a view showing an example of the file management table possessed byeach of the removable storage medium 20, storage unit 121, and memory122, and FIG. 3 is a view showing an example of the block managementtable possessed by each of the removable storage medium 20, storage unit121, and memory 122. In the file management table, a file ID of thevideo file, file name, and number of the logical blocks in which thevideo file is recorded are shown. It should be noted that the logicalblock indicates a minimum management unit of a storage area on theremovable storage medium 20 and storage unit 121, and the video file iswritten/read in units of a logical block. Further, in the blockmanagement table, a logical block No., usage state of the logical block,ID of a device to which the logical block belongs, and physical addressof the logical block are shown. It should be noted that in thisembodiment, a device ID: D001 indicates a removable storage medium 20,and device ID: D002 indicates a storage unit 121. Further, video data iswritten to the logical blocks of the removable storage medium 20 andstorage unit 121 as shown in, for example, FIG. 4.

FIG. 5 is a sequence diagram of a case where the video data processingsystem 10 according to the first embodiment of the present inventionprepares to transfer a video file recorded on the removable storagemedium 20 to the storage unit 121, and prepares to carry out non-linearediting of the video file by using the non-linear editing unit 30.Further, FIG. 6 is a schematic view showing the states of the removablestorage medium 20, memory 122, and storage unit 121 in the case wherethe video data processing system 10 carries out the processing shown inFIG. 5. FIG. 6A shows the states of the removable storage medium 20.FIG. 6B shows the states of the memory 122. FIG. 6C shows the states ofthe storage unit 121.

In FIG. 5, when the removable storage medium 20 is set, the reading unit11 notifies the processing unit 123 that the removable storage medium 20is set. On receiving the notification indicating that the removablestorage medium 20 is set, the processing unit 123 causes the readingunit 11 to read information about the file management table. The readingunit 11 outputs the information about the file management table of theremovable storage medium 20 to the processing unit 123.

The processing unit 123 updates the file management table of the memory122 on the basis of the information about the file management table(S51). As a result of this, the information of the file management tableof the removable storage medium 20 is written to the file managementtable of the memory 122.

Subsequently, the processing unit 123 calculates a storage areanecessary for recording video contents 1 to 3 on the storage unit 121,and secures a logical block of the storage unit 121 on the basis of thecalculated storage area (S52). As a result of this, in the storage unit121, logical block Nos.: L105 and L106 for recording the video content 1are secured, logical block Nos.: L107 to L109 for recording the videocontent 2 are secured, and logical block Nos.: L120 to L122 forrecording the video content 3 are secured. On completing securing thestorage area in the storage unit 121, the processing unit 123 notifiesthe completion to the reading unit 11, which, as a result, outputsinformation about the block management table of the removable storagemedium 20 to the processing unit 123. The processing unit 123 updatesthe block management table of the memory 122 on the basis of theinformation about the block management table (S53).

When the removable storage medium 20 is set at the reading unit 11 asdescribed above, the video data processing system 10 updates the filemanagement table and the block management table of the memory 122 on thebasis of the file management table and the block management table of theremovable storage medium 20. As a result of this, in the memory 122, themanagement tables of the removable storage medium 20 are managed. Thatis, it can be considered that the video file recorded on the removablestorage medium 20 is virtually recorded on the video server 12.

Processing to be performed after the preparation for transfer of thevideo file recorded on the removable storage medium 20 to the storageunit 121, and the preparation for non-linear editing of the video fileby using the non-linear editing unit 30 have been completed by theprocessing shown in FIG. 5 will be described below.

First, the case where after the processing shown in FIG. 5 is completed,the video file is transferred from the removable storage medium 20 tothe storage unit 121 in the background will be described below. FIG. 7is a sequence diagram at the time. Further, FIG. 8 is a schematic viewshowing the states of the removable storage medium 20, memory 122, andstorage unit 121 in the case where the video data processing system 10carries out the processing shown in FIG. 7. FIG. 8A shows the states ofthe removable storage medium 20. FIG. 8B shows the states of the memory122. FIG. 8C shows the states of the storage unit 121.

In FIG. 7, the processing unit 123 gives an instruction to transfer thevideo content 1 which is the video file recorded on the removablestorage medium 20 to the reading unit 11. On receiving the instruction,the reading unit 11 transfers the video content 1 to the video server 12in units of video data. The processing unit 123 records the video datatransferred from the removable storage medium 20 on an unassignedaddress: h00000004 of the storage unit 121 (S71). The processing unit123 updates the block management table of the memory 122 on the basis ofthe write location of the video data in the storage unit 121, sets thedevice ID of the logical block No.: L001 to D002, and sets the physicaladdress to h00000004 (S72).

When the block management table of the memory 122 is updated, theprocessing unit 123 gives the reading unit 11 an instruction to transferthe next video data. The reading unit 11 reads the next video data fromthe removable storage medium 20, and transfers the video data to thevideo server 12. The processing unit 123 records the video datatransferred from the removable storage medium 20 on an unassignedaddress: h00000005 of the storage unit 121 (S73). When the recording ofthe video data is completed, the processing unit 123 updates the blockmanagement table of the memory 122 on the basis of the write location ofthe video data in the storage unit 121, sets the device ID of thelogical block No.: L002 to D002, and sets the physical address toh00000005 (S74). As a result of this, the video content 1 is transferredfrom the removable storage medium 20 to the storage unit 121.

The video data processing system 10 repeats the processing of S71 to S74to transfer the video contents 2 and 3 which are video files recorded onthe removable storage medium 20 to the storage unit 121. Further, oncompleting the transfer of the video files recorded on the removablestorage medium 20, the reading unit 11 notifies the video server 12 thatthe transfer of the video files recorded on the removable storage medium20 has been completed. On receiving the notification indicating that thetransfer has been completed, the processing unit 123 updates the blockmanagement table of the storage unit 121 on the basis of the blockmanagement table of the memory 122 (S75). That is, the device IDs andphysical addresses of the logical block Nos.: L105 to L109, and L120 toL122 in the storage unit 121 are rewritten to be changed to the deviceIDs and physical addresses of the logical block Nos.: L001 to L005, andL010 to L012 in the memory 122, and the states of the logical blockNos.: L105 to L109, and L120 to L122 in the storage unit 121 arerewritten to be changed to busy (in use). Subsequently, the processingunit 123 updates the file management table of the storage unit 121 onthe basis of the file management table of the memory 122. That is, thevideo contents 1 to 3 transferred from the removable storage medium 20are written to the file management table of the storage unit 121 (S76).As a result of this, the transfer processing is completed.

As described above, the processing unit 123 transfers the video datafrom the reading unit 11 to the storage unit 121, and updates the blockmanagement table of the memory 122. Further, if the transfer of thevideo data is completed, the processing unit 123 updates the filemanagement table and the block management table of the storage unit 121on the basis of the file management table and the block management tableof the memory 122. As a result of this, in the video data processingsystem, it becomes possible, after the completion of the video filetransfer, to merge the file management table and the block managementtable of the memory 122 into the file management table and the blockmanagement table of the storage unit 121. Accordingly, it becomespossible to improve the transfer efficiency of the video file. It shouldbe noted that this transfer processing can be executed while thenon-linear editing is executed by the non-linear editing unit 30.

In the case where the storage media of the removable storage medium 20and storage unit 121 are semiconductor storage media, it can be assumedthat the storage unit 121 is higher than the reading unit 11 in theinput/output performance of the video data. In this case, the videofiles with the stronger possibility of being accessed are transferred tothe video server earlier, whereby it becomes possible to improve theresponse speed with respect to the editing operation. Specific examplesof the above will be shown below.

The processing unit 123 may give a transfer instruction to the readingunit 11 in such a manner that video data of a plurality of consecutivelogical blocks on which video files which become objects of readrequests are recorded is preferentially transferred. As a result ofthis, it becomes possible to preferentially transfer video data with thestronger possibility of being accessed to the storage unit 121.

The processing unit 123 may give a transfer instruction to the readingunit 11 in such a manner that a video file in which the creation time,update time or the like is close to that of the video file that has beenrequested to be read is preferentially transferred.

The processing unit 123 may give a transfer instruction to the readingunit 11 in such a manner that a video file in which the creation time isthe latest is preferentially transferred.

The processing unit 123 may give a transfer instruction to the readingunit 11 in such a manner that video data of a logical block on which theleading head of the video file is recorded for the convenience ofpreview or the like is preferentially transferred.

An order determination unit for determining the transfer order of videodata by predicting a video file which will become an object of a readrequest from the past tendency of access from the non-linear editingunit 30 is provided in the video server 12. Further, the processing unit123 may give a transfer instruction to the reading unit 11 in such amanner that the video data are transferred preferentially in accordancewith the order determined by the order determination unit.

Next, the case where after the preparation of FIG. 5 is completed, arequest to read a video file recorded on the removable storage medium 20is received from the non-linear editing unit 30 will be described below.FIG. 9 is a sequence diagram at that time.

In FIG. 9, on receiving a request to read the video file from thenon-linear editing unit 30, the processing unit 123 refers to the filemanagement table of the memory 122 to specify a logical block to beaccessed. When the logical block to be accessed is specified, theprocessing unit 123 refers to the device ID and physical address shownin the block management table of the memory 122 to determine whether ornot the video file which is requested to be read has already beentransferred to the storage unit 121 (S91). That is, the processing unit123 determines whether the video data of the video file is recorded onone of the removable storage medium 20 or storage unit 121.

When the video data of the video file is recorded on the storage unit121, the processing unit 123 transfers the read request to the storageunit 121. On receiving the read request, the storage unit 121 outputs insequence the video data of the video file which is requested to be readto the non-linear editing unit 30.

In the case where the video data of the video file is recorded on theremovable storage medium 20, the processing unit 123 transfers the readrequest to the reading unit 11 (S92). On receiving the read request, thereading unit 11 reads the video data of the video file which isrequested to be read from the removable storage medium 20. Theprocessing unit 123 outputs in sequence the video data read by thereading unit 11 to the non-linear editing unit 30 (S93).

When the processing unit 123 outputs the video data to the non-linearediting unit 30, the unit 123 writes the video data to the storage unit121 in sequence (S94). On completing the recording of the video data onthe storage unit 121, the processing unit 123 updates the blockmanagement table of the memory 122 on the basis of the write location ofthe video data (S95). Further, on completing the transfer of the videofile to the storage unit 121, the processing unit 123 updates the filemanagement table and the block management table of the storage unit 121on the basis of the file management table and the block management tableof the memory 122 (S96).

When the output of the video file requested by the non-linear editingunit 30 is completed, the processing unit 123 notifies the non-linearediting unit 30 that the output of the video file is completed.

FIG. 10 is a schematic view showing the states of the removable storagemedium 20, memory 122, and storage unit 121 in the case where a requestto read the video content 1 is input from the non-linear editing unit30. FIG. 10A shows the states of the removable storage medium 20. FIG.10B shows the states of the memory 122. FIG. 10C shows the states of thestorage unit 121.

On receiving the read request of the video content 1 from the non-linearediting unit 30, the processing unit 123 refers to the file managementtable and the block management table of the memory 122 to determine thatthe video content 1 is recorded on the removable storage medium 20(S91). The processing unit 123 transfers the read request of the videocontent 1 to the reading unit 11 (S92). On receiving the read request,the reading unit 11 reads the video data of the video content 1 from theremovable storage medium 20 (S93). The processing unit 123 outputs theread video data to the non-linear editing unit 30 in sequence.

When the processing unit 123 outputs the video data of the video content1 to the non-linear editing unit 30, the unit 123 writes the video datain sequence to the video server 12 (S94). As a result of this, the videodata transferred from the removable storage medium 20 is recorded on theunassigned addresses: h00000004 and h00000005 of the storage unit 121.When the processing unit 123 has written the video data to the logicalblock of the storage unit 121, the unit 123 updates the block managementtable of the memory 122 on the basis of the write location thereof(S95). As a result of this, the device IDs of the logical block Nos.:L001 and L002 of the memory 122 become D002, and the physical addressesbecome h00000004 and h00000005. Further, on completing the transfer ofthe video content 1, the processing unit 123 updates the file managementtable and the block management table of the storage unit 121 on thebasis of the file management table and the block management table of thememory 122 (S96).

As described above, in the video data processing system 10, if the readrequest of the video file is input from the non-linear editing unit 30,the storage position of the video data of the requested video file isdetermined by referring to the file management table and the blockmanagement table of the memory 122. Further, if the storage position ofthe video data is determined, the processing unit 123 outputs the videofile to the non-linear editing unit 30 by reading the video data insequence from the storage position of the video data. As a result ofthis, it becomes possible for the video data processing system 10 tooutput the video file to the non-linear editing unit 30, even if thevideo file of the removable storage medium 20 has not been transferredto the storage unit 121. That is, it is possible for the non-linearediting unit 30 to start non-linear editing of the video file even ifthe video file recorded on the removable storage medium 20 has not beentransferred to the storage unit 121.

In the case where a video file which will become an object of a readrequest is recorded on the removable storage medium 20, the video dataprocessing system 10 outputs the video data thereof to the non-linearediting unit 30, and simultaneously writes the video data to the storageunit 121. As a result of this, the transfer efficiency of the video fileis improved.

Next, the case where after the preparation of FIG. 5 is completed, awrite request of an edited video file is received from the non-linearediting unit 30 will be described below. FIG. 11 is a sequence diagramat that time. Further, FIG. 12 is a schematic view showing the states ofthe removable storage medium 20, memory 122, and storage unit 121 in thecase where a write request of the edited video 1 is input from thenon-linear editing unit 30. FIG. 12A shows the states of the removablestorage medium 20. FIG. 12B shows the states of the memory 122. FIG. 12Cshows the states of the storage unit 121.

In FIG. 11, on receiving a write request of an edited video file: theedited video 1 from the non-linear editing unit 30, the processing unit123 transfers the write request to the storage unit 121 to write theedited video 1 to the storage unit 121 (S111). As a result of this, theedited video 1 is written to the logical block (physical address:h00000004) of the storage unit 121. Further, the processing unit 123updates the file management table and the block management table of thestorage unit 121 (S112). The processing unit 123 updates the filemanagement table and the block management table of the memory 122 on thebasis of the write location of the video data in the storage unit 121(S113).

As described above, after recording the edited video file on the storageunit 121, the processing unit 123 updates the file management table andthe block management table of the memory 122 on the basis of the filemanagement table and the block management table of the storage unit 121.As a result of this, in the video data processing system, the editedvideo file is always recorded on the storage unit 121, and the videofile recorded on the storage unit 121 is also managed at the memory 122.

From the above description, according to the video data processingsystem of the present invention, it is possible to start non-linearediting of the acquired video file without waiting time.

In the video data processing system according to this embodiment, in thefile management table of each of the removable storage medium 20, memory122, and storage unit 121, a unique file ID is imparted to each videofile. As a result of this, it becomes possible to limit transfer ofvideo files with the same file ID by collating the file ID of a videofile transferred from the removable storage medium 20 to the storageunit 121 and the file ID of a video file recorded on the storage unit121 with each other.

It should be noted that the processing of the video data processingsystem according to this embodiment is not limited to theabove-mentioned content. For example, the transfer of the video filedoes not necessarily conform to the sequence shown in FIG. 7, and canalso be carried out in accordance with the sequence shown in FIG. 13.FIG. 14 is a schematic view showing the states of the removable storagemedium 20, memory 122, and storage unit 121 in the case where the videodata processing system 10 carries out the processing shown in FIG. 13.FIG. 14A shows the states of the removable storage medium 20. FIG. 14Bshows the states of the memory 122. FIG. 14C shows the states of thestorage unit 121.

That is, in FIG. 13, the processing unit 123 updates the blockmanagement table of the storage unit 121 on the basis of the blockmanagement table of the memory 122 (S131). That is, the states of thelogical block Nos.: L105 to L109 and L120 to L122 are rewritten to bechanged to “busy (in use)”, the device ID is rewritten to be changed toD001, and the physical address is rewritten to be changed to the samephysical address as the physical address of the memory 122.Subsequently, the processing unit 123 updates the file management tableof the storage unit 121 on the basis of the file management table of thememory 122 (S132). That is, the video contents 1 to 3 recorded on theremovable storage medium 20 are written to the file management table ofthe storage unit 121.

When the file management table of the storage unit 121 is updated, theprocessing unit 123 gives an instruction to transfer the video content 1which is a video file recorded on the removable storage medium 20 to thereading unit 11. On receiving this instruction, the reading unit 11transfers the video content 1 to the video server 12 in units of videodata. The processing unit 123 records the video data transferred fromthe removable storage medium 20 on the unassigned address: h00000004 ofthe storage unit 121 (S133).

The processing unit 123 updates the block management table of the memory122 on the basis of the write location of the video data in the storageunit 121, sets the device ID of the logical block No.: L001 to D002, andsets the physical address to h00000004 (S134). Further, the processingunit 123 updates the block management table of the storage unit 121 onthe basis of the write location of the video data in the storage unit121, sets the device ID of the logical block No.: L105 to D002, and setsthe physical address to h00000004 (S135).

Having updated the block management tables of the memory 122 and storageunit 121, the processing unit 123 gives an instruction to transfer thenext video data to the reading unit 11. The reading unit 11 reads thenext video data from the removable storage medium 20, and transfers thevideo data to the video server 12 (S136). The processing unit 123records the video data transferred from the removable storage medium 20on the unassigned address: h00000005 of the storage unit 121.

The processing unit 123 updates the block management table of the memory122 on the basis of the write location of the video data in the storageunit 121, sets the device ID of the logical block No.: L002 to D002, andsets the physical address to h00000005 (S137). Further, the processingunit 123 updates the block management table of the storage unit 121 onthe basis of the write location of the video data in the storage unit121, sets the device ID of the logical block No.: L106 to D002, and setsthe physical address to h00000005 (S138). As a result of this, the videocontent 1 is transferred from the removable storage medium 20 to thestorage unit 121.

The video data processing system 10 repeats the processing of S133 toS138 to transfer the video contents 2 and 3 which have been written tothe file management table and the block management table of the storageunit 121 by the processing of 5131 and S132 from the removable storagemedium 20 to the storage unit 121.

As a result of this, even before the video file is transferred from theremovable storage medium 20 to the storage unit 121, the file managementtable and the block management table of the removable storage medium 20are merged into the file management table and the block management tableof the storage unit 121. Thus, in the file management table and theblock management table of the storage unit 121, the video file recordedon the removable storage medium 20 is also managed.

In the video data processing system according to this embodiment, thetransfer processing of the video file may be carried out in thefollowing manner to improve the performance of the editing processing tobe carried out by the non-linear editing unit 30.

That is, If the read request or write request is not input from thenon-linear editing unit 30 for a predetermined time, the processing unit123 may give a transfer instruction to the reading unit 11. As a resultof this, while the processing for the read request or write request fromthe non-linear editing unit 30 is carried out, the video data processingsystem 10 does not carry out transfer of the video file in thebackground. That is, it becomes possible for the video data processingsystem 10 to make the editing operation prior to the transfer of thevideo file.

The processing unit 123 may be provided with a cache for temporarilystoring video data transferred from the removable storage medium 20 tothe storage unit 121, and may refer to the cache data to output thevideo data of the video file which has been requested to be read to thenon-linear editing unit 30.

Second Embodiment

FIG. 15 is a schematic view showing the configuration of a video dataprocessing system 50 according to a second embodiment of the presentinvention. The video data processing system 50 is provided with areading unit 11, a gateway server 51, and a video server 52. Anon-linear editing unit 30 is connected to the gateway server 51.

A video file recorded on a removable storage medium 20 is read by thereading unit 11, and is transferred to the video server 52 through thegateway server 51 to be recorded.

The video server 52 is provided with, for example, a semiconductorstorage medium such as a flash memory and the like, or a storage mediumsuch as a hard disk and the like, and records a video file transferredthereto. On the video server 52, a file management table for managingthe recorded video file, and a block management table for managing therecording state of the storage medium are recorded in advance. The videoserver 52 updates these tables in accordance with an instruction fromthe gateway server 51.

The gateway server 51 is provided with a processing unit 511, and amemory 512. The processing unit 511 is embodied as a controller forcontrolling the memory 512 and the video server 52, and is configured bya microprocessor such as a CPU or the like. As the memory 512, forexample, a RAM is used.

When the removable storage medium 20 is connected to the reading unit11, the processing unit 511 updates the file management table and theblock management table recorded in advance on each of the memory 512 andvideo server 52, prepares to transfer a video file recorded on theremovable storage medium 20 to the video server 52, and prepares tocarry out non-linear editing of the video file by using the non-linearediting unit 30.

If the preparation for transfer of the video file recorded on theremovable storage medium 20 is completed, the processing unit 511transfers the video file to the video server 52, and updates the filemanagement tables and block management tables of the memory 512 andvideo server 52.

If the processing unit 511 receives a request to read the video filefrom the non-linear editing unit 30, the unit 123 outputs the requestedvideo file to the non-linear editing unit 30 by referring to the filemanagement tables and block management tables recorded on the removablestorage medium 20, memory 512, and video server 52.

If the processing unit 511 receives a request to write the video filefrom the non-linear editing unit 30, the unit 511 transfers the videofile to the video server 52, and causes the video server 52 to recordthe video file. Further, the processing unit 511 updates the filemanagement tables and block management tables of the video server 52 andmemory 512.

The non-linear editing unit 30 accesses the gateway server 51, andrequests the gateway server 51 to read a video file desired to beedited. Further, the non-linear editing unit 30 requests the gatewayserver 51 to write the video file that has already been edited.

Next, the processing operation of the video data processing system 50configured as described above will be described below. It should benoted that in this embodiment, a device ID: D001 indicates the removablestorage medium 20, and device ID: D002 indicates the video server 52.

FIG. 16 is a sequence diagram of a case where the video data processingsystem 50 according to the second embodiment of the present inventionprepares to transfer a video file recorded on the removable storagemedium 20 to the video server 52, and prepares to carry out non-linearediting of the video file by using the non-linear editing unit 30.Further, FIG. 17 is a schematic view showing the states of the removablestorage medium 20, gateway server 51, and video server 52 in the casewhere the video data processing system 50 carries out the processingshown in FIG. 16. FIG. 17A shows the states of the removable storagemedium 20. FIG. 17B shows the states of the gateway server 51. FIG. 17Cshows the states of the video server 52.

In FIG. 16, when the removable storage medium 20 is set, the readingunit 11 notifies the gateway server 51 that the removable storage medium20 is set. On receiving the notification indicating that the removablestorage medium 20 is set, the processing unit 511 requests the readingunit 11 to provide information about the file management table. Thereading unit 11 outputs the information about the file management tableof the removable storage medium 20 to the gateway server 51.

The processing unit 511 updates the file management table of the memory512 on the basis of the information about the file management table(S161). As a result of this, the information of the file managementtable of the removable storage medium 20 is written to the filemanagement table of the memory 512.

Subsequently, the processing unit 511 calculates a storage areanecessary for recording video contents 1 to 3 on the storage unit 121(S162), and issues an instruction to secure a logical block on the basisof the calculated storage area to the video server 52 (S163). The videoserver 52 secures, on the basis of the calculated result, logical blockNos.: L105 and L106 to record the video content 1, secures logical blockNos.: L107 to L109 to record the video content 2, and secures logicalblock Nos.: L120 to L122 to record the video content 3. The video server52 notifies the processing unit 511 that securing the storage area iscomplete. On receiving the notification, the processing unit 511transfers it to the reading unit 11, which, as a result, outputsinformation about the block management table of the removable storagemedium 20 to the processing unit 511. The processing unit 511 updatesthe block management table of the memory 512 on the basis of theinformation about the block management table (S164).

If the removable storage medium 20 is set at the reading unit 11 asdescribed above, the video data processing system 50 updates the filemanagement table and the block management table of the memory 512 on thebasis of the file management table and the block management table of theremovable storage medium 20. That is, in the memory 512, the managementtable of the removable storage medium 20 is managed. As a result ofthis, it can be considered that the video file recorded on the removablestorage medium 20 is virtually recorded on the video server 52.

Processing to be performed after the preparation for transfer of thevideo file recorded on the removable storage medium 20 to the videoserver 52, and the preparation for non-linear editing of the video fileby using the non-linear editing unit 30 have been completed by theprocessing shown in FIG. 16 will be described below.

First, the case where after the processing shown in FIG. 16 iscompleted, the video file is transferred from the removable storagemedium 20 to the video server 52 in the background will be describedbelow. FIG. 18 is a sequence diagram at the time. Further, FIG. 19 is aschematic view showing the states of the removable storage medium 20,gateway server 51, and video server 52 in the case where the video dataprocessing system 50 carries out the processing shown in FIG. 18. FIG.19A shows the states of the removable storage medium 20. FIG. 19B showsthe states of the gateway server 51. FIG. 19C shows the states of thevideo server 52.

In FIG. 18, the processing unit 511 gives an instruction to transfer thevideo content 1 which is the video file recorded on the removablestorage medium 20 to the reading unit 11. On receiving the instruction,the reading unit 11 transfers the video content 1 to the video server 12in units of video data (S181). The video server 52 receives the videodata transferred from the removable storage medium 20, and records thevideo data on an unassigned address: h00000004. On completing therecording of the video data, the video server 52 notifies the gatewayserver 51 of the write location of the video data. The processing unit511 updates the block management table of the memory 512 on the basis ofthe notified write location, sets the device ID of the logical blockNo.: L001 to D002, and sets the physical address to h00000004 (S182).

When the block management table of the memory 512 is updated, theprocessing unit 511 gives the reading unit 11 an instruction to transferthe next video data. The reading unit 11 reads the next video data fromthe removable storage medium 20, and transfers the video data to thevideo server 52 (S183). The video server 52 receives the video datatransferred from the removable storage medium 20, and records the videodata on an unassigned address: h00000005. When the recording of thevideo data is completed, the video server 52 notifies the gateway server51 of the write location of the video data. The processing unit 511updates the block management table of the memory 512 on the basis of thenotified write location, sets the device ID of the logical block No.:L002 to D002, and sets the physical address to h00000005 (S184). As aresult of this, the video content 1 is transferred from the removablestorage medium 20 to the video server 52.

The video data processing system 50 repeats the processing of S181 toS184 to transfer the video contents 2 and 3 which are video filesrecorded on the removable storage medium 20 to the video server 52.Further, on completing the transfer of the video files recorded on theremovable storage medium 20, the reading unit 11 notifies the gatewayserver 51 that the transfer of the video files recorded on the removablestorage medium 20 has been completed. On receiving the notificationindicating that the transfer has been completed, the processing unit 511outputs information about the block management table of the memory 512to the video server 52. The video server 52 updates the block managementtable on the basis of the information supplied from the gateway server51 (S185). That is, the device IDs and physical addresses of the logicalblock Nos.: L105 to L109, and L120 to L122 in the video server 52 arerewritten to be changed to the device IDs and physical addresses of thelogical block Nos.: L001 to L005, and L010 to L012 in the memory 512,and the states of the logical block Nos.: L105 to L109, and L120 to L122in the video server 52 are rewritten to be changed to “busy (in use)”.Subsequently, the processing unit 511 outputs information about the filemanagement table of the memory 512 to the video server 52. The videoserver 52 updates the file management table on the basis of theinformation supplied from the gateway server 51 (S186). That is, thevideo contents 1 to 3 transferred from the removable storage medium 20are written to the file management table of the video server 52. As aresult of this, the transfer processing is completed.

As described above, the processing unit 511 transfers the video datafrom the reading unit 11 to the video server 52, and updates the blockmanagement table of the memory 512. Further, if the transfer of thevideo data is completed, the processing unit 511 updates the filemanagement table and the block management table of the video server 52on the basis of the file management table and the block management tableof the memory 512. As a result of this, in the video data processingsystem 50, it becomes possible, after the completion of the video filetransfer, to merge the file management table and the block managementtable of the memory 512 into the file management table and the blockmanagement table of the video server 52. Accordingly, it becomespossible to improve the transfer efficiency of the video file. It shouldbe noted that this transfer processing can be executed while thenon-linear editing is executed by the non-linear editing unit 30.

The video files with the stronger possibility of being accessed aretransferred to the video server earlier, whereby it becomes possible toimprove the response speed with respect to the editing operation.Specific examples of the above will be shown below.

The processing unit 511 may give a transfer instruction to the readingunit 11 in such a manner that video data of a plurality of consecutivelogical blocks on which video files which become objects of readrequests are recorded is preferentially transferred. As a result ofthis, video data with the stronger possibility of being accessed istransferred to the video server 52.

The processing unit 511 may give a transfer instruction to the readingunit 11 in such a manner that a video file in which the creation time,update time or the like is close to that of the video file that has beenrequested to be read is preferentially transferred.

The processing unit 511 may give a transfer instruction to the readingunit 11 in such a manner that a video file in which the creation time isthe latest is preferentially transferred.

The processing unit 511 may give a transfer instruction to the readingunit 11 in such a manner that video data of a logical block on which theleading head of the video file is recorded for the convenience ofpreview or the like is preferentially transferred.

An order determination unit is further provided in the gateway server51. Further, the processing unit 511 may give a transfer instruction tothe reading unit 11 in such a manner that the video data are transferredpreferentially in accordance with the order determined by the orderdetermination unit.

Next, the case where after the preparation of FIG. 16 is completed, arequest to read a video file recorded on the removable storage medium 20is received from the non-linear editing unit 30 will be described below.FIG. 20 is a sequence diagram at that time.

In FIG. 20, on receiving a request to read the video file from thenon-linear editing unit 30, the processing unit 511 refers to the filemanagement table of the memory 512 to specify a logical block to beaccessed. When the logical block to be accessed is specified, theprocessing unit 511 refers to the device ID and physical address shownin the block management table of the memory 512 to determine whether ornot the video file which is requested to be read has already beentransferred to the video server 52 (S201). That is, the processing unit511 determines whether the video data of the video file is recorded onone of the removable storage medium 20 or video server 52.

When the video data of the video file is recorded on the video server52, the processing unit 511 transfers the read request to the videoserver 52. On receiving the read request, the video server 52 outputs insequence the video data of the video file which is requested to be readto the gateway server 51. The processing unit 511 transfers in sequencethe video data output from the video server 52 to the non-linear editingunit 30.

In the case where the video data of the video file is recorded on theremovable storage medium 20, the processing unit 511 transfers the readrequest to the reading unit 11 (S202). On receiving the read request,the reading unit 11 reads the video data of the video file which isrequested to be read from the removable storage medium 20. Theprocessing unit 511 transfers in sequence the video data read by thereading unit 11 to the non-linear editing unit 30 (S203).

When the processing unit 511 transfers the video data to the non-linearediting unit 30, the unit 511 transfers the video data to the videoserver 52 in sequence (S204). The video server 52 receives the videodata transferred in sequence from the gateway server 51, and records thevideo data on an unassigned address. On completing the recording of thevideo data, the video server 52 notifies the processing unit 511 of thewrite location of the video data. The processing unit 511 updates theblock management table of the memory 512 on the basis of the notifiedwrite location (S205). Further, on completing the transfer of the videofile to the video server 52, the processing unit 511 updates the filemanagement table and the block management table of the video server 52on the basis of the file management table and the block management tableof the memory 512 (S206).

When the output of the video file requested by the non-linear editingunit 30 is completed, the processing unit 511 notifies the non-linearediting unit 30 that the output of the video file is completed.

FIG. 21 is a schematic view showing the states of the removable storagemedium 20, gateway server 51, and video server 52 in the case where arequest to read the video content 1 is input from the non-linear editingunit 30. FIG. 21A shows the states of the removable storage medium 20.FIG. 21B shows the states of the gateway server 51. FIG. 21C shows thestates of the video server 52.

On receiving the read request of the video content 1 from the non-linearediting unit 30, the processing unit 511 refers to the file managementtable and the block management table of the memory 512 to determine thatthe video content 1 is recorded on the removable storage medium 20(S201). The processing unit 511 transfers the read request of the videocontent 1 to the reading unit 11 (S202). On receiving the read request,the reading unit 11 reads the video data of the video content 1 from theremovable storage medium 20. The processing unit 511 transfers the readvideo data to the non-linear editing unit 30 in sequence (S203).

When the processing unit 511 outputs the video data of the video content1 to the non-linear editing unit 30, the unit 511 transfers the videodata in sequence to the video server 12 (S204). The video server 52receives the transferred video data, and records the video data insequence on the unassigned addresses: h00000004 and h00000005. Oncompleting the recording of the video data, the video server 52 notifiesthe processing unit 511 of the write location of the video data. Theprocessing unit 511 updates the block management table of the memory 512on the basis of the notified write location (S205), sets the device IDsof the logical block Nos.: L001 and L002 of the memory 512 to D002, andsets the physical addresses to h00000004 and h00000005. Further, oncompleting the transfer of the video content 1, the processing unit 511updates the file management table and the block management table of thevideo server 52 on the basis of the file management table and the blockmanagement table of the memory 512 (S206).

As described above, in the video data processing system 50, if the readrequest of the video file is input from the non-linear editing unit 30,the storage position of the video data of the requested video file isdetermined by referring to the management tables of the memory 512.Further, if the storage position of the video data is determined, theprocessing unit 511 transfers the video data read from storage positionin sequence to the non-linear editing unit 30. As a result of this, itbecomes possible for the video data processing system 50 to transfer thevideo file to the non-linear editing unit 30, even if the video file ofthe removable storage medium 20 has not been transferred to the videoserver 52. That is, it is possible for the non-linear editing unit 30 tostart non-linear editing of the video file even if the video filerecorded on the removable storage medium 20 has not been yet transferredto the video server 52.

In the case where a video file which will become an object of a readrequest is recorded on the removable storage medium 20, the video dataprocessing system 50 outputs the video data thereof to the non-linearediting unit 30, and simultaneously writes the video data to the videoserver 52. As a result of this, the transfer efficiency of the videofile is improved.

Next, the case where after the preparation of FIG. 16 is completed, awrite request of an edited video file is received from the non-linearediting unit 30 will be described below. FIG. 22 is a sequence diagramat that time. Further, FIG. 23 is a schematic view showing the states ofthe removable storage medium 20, gateway server 51, and video server 52in the case where a write request of the edited video 1 is input fromthe non-linear editing unit 30.

In FIG. 22, on receiving a write request of an edited video file: theedited video 1 from the non-linear editing unit 30, the processing unit511 transfers the write request to the video server 52. On receiving thewrite request, the video server 52 writes the video data of the editedvideo 1 to the physical address: h00000004 (S221). Further, oncompleting the writing of the video data, the video server 52 updatesthe file management table and the block management table (S222), andnotifies the gateway server 51 of the write location of the video data.The processing unit 511 updates the file management table and the blockmanagement table of the memory 512 on the basis of the notification ofthe write location from the video server 52 (S223).

As described above, on receiving the write request of the edited videofile, the gateway server 51 transfers the video file to the video server52 to cause the video server 52 to record the video file. Further, aftercausing the video server 52 to record the video file, the gateway server51 updates the file management table and the block management table ofthe memory 512 on the basis of the file management table and the blockmanagement table of the video server 52. As a result of this, in thevideo data processing system 50, the edited video file is also managedat the memory 512 of the gateway server 51.

From the above description, according to the video data processingsystem of the present invention, it is possible to start non-linearediting of the acquired video file without waiting time.

Other Embodiments

It should be noted that the present invention is not limited to theembodiments described above. For example, in each of the above-mentionedembodiments, the case where the reading unit 11 reads the video file andmanagement tables from the removable storage medium 20, the video fileand management tables being recorded on the inside of the medium 20, hasbeen described. However, the operation of the reading unit 11 is notlimited to reading data from the removable storage medium 20. Forexample, in the case where the camera is provided with an incorporatedstorage medium, the reading unit 11 may directly read the video file andmanagement tables from the incorporated storage medium of the camera.

In each of the above embodiments, the example in which a semiconductorstorage medium such as a flash memory and the like, or a storage mediumsuch as a hard disk and the like is used is described. Here, in the casewhere a disk medium is used as the removable storage medium 20, if aplurality of processing items are simultaneously executed, theprocessing changeover overhead is large because of the seek time.Accordingly, in the present invention, employing a semiconductor storagemedium such as a flash memory and the like as the removable storagemedium 20 makes it possible to efficiently carry out the processing ifan access for the editing operation and transfer processing of videodata are concurrently carried out.

In each of the above embodiments, the example in which a read requestand write request concomitant with the editing processing carried out bythe non-linear editing unit 30 are received has been described. However,the access from outside is not limited to the non-linear editing unit30. For example, a case where access processing is applied to the videoserver by a decoder device or the like is also practicable.

In each of the above embodiments, the example in which the terminalaccessing from outside is only the non-linear editing unit 30 has beendescribed. However, the external terminal is not limited to one. Itshould be noted that in the case where there are a plurality of externalterminals, an order imparting unit for imparting the priority order toeach of the external terminals may further be provided in the videoserver 12 or gateway server 51. As a result of this, if read requestsare received from the plurality of external terminals, it becomespossible for the video server 12 or gateway server 51 to preferentiallytransfer video data to external terminals to which high priority orderis imparted by the order imparting unit.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

1-23. (canceled)
 24. A gateway server used in a system for reading videodata items included in a video content from a storage medium by areading unit to record the video data items on a video server, the videodata items being recorded in corresponding first logical blocks in thestorage medium, wherein the reading unit which is connected to thestorage medium to generate a setting signal, and reads first managementinformation including first physical addresses specifying blocks wherethe video data items are recorded in response to the setting signal, andreads the video data items from the first logical blocks, the videoserver which includes second logical blocks to record the video dataitems transferred from the reading unit in the second logical blocks andstores second management information including second physical addressesspecifying blocks where the video data items are recorded, said gatewayserver comprising; a memory which stores third management informationincluding the first or second physical addresses; and a controller whichwrites the first physical addresses included in the first managementinformation as the third management information in the memory inresponse to the setting signal, updates the first physical addressesincluded in the third management information to the second physicaladdresses upon reception of the video data items by the video serverfrom the reading unit, outputs the video data items read from thereading unit if the third management information includes the firstphysical addresses, and outputs the video data items read from the videoserver if the third management information includes the second physicaladdresses in response to a read request for the video content includingthe video data items from an external device.
 25. (canceled)
 26. Thegateway server according to claim 24, wherein the first managementinformation, the second management information, and the third managementinformation each includes a file name identifying a video content, andthe controller limits transfer of video data in a video content whichhave already been transferred from the reading unit to the video serverby comparing the file name in the first management information with thefile name in the second management information.
 27. The gateway serveraccording to claim 24, wherein if there is no read request and no writerequest within a preset period of time, the controller transfers the ofvideo data items from the reading unit to the video server.
 28. Thegateway server according to claim 24, wherein the controller is providedwith a cache for temporarily storing video data items transferred fromthe reading unit to the video server, and the controller outputs thevideo data items stored in the cache to the external device in responseto the read request.
 29. The gateway server according to claim 24,wherein the controller preferentially transfers video data items in avideo content which has a high possibility to be designated by the readrequest from the reading unit to the video server.
 30. The gatewayserver according to claim 24, further comprising, an order impartingunit which imparts the priority order to each of a plurality of externaldevices which output the read requests, wherein the controller outputsvideo data items in the video content designated by the read requestfrom the external device which has higher priority to the other externaldevices. 31-33. (canceled)